Applied Immune Sciences, Inc. has developed sterile polystyrene devices onto which monoclonal antibodies are covalently attached. These devices are routinely used to rapidly separate cells with surface antigens specific for the immobilized antibody. Morover, these devices have been used successfully to purify hematopoietic stem cells from human bone marrow. The specific aim of this research proposal is to use these devices to efficiently collect peripheral blood stem cells from autologous transplant candidates, thereby creating a nontoxic generic procedure to prepare purged grafts. Moreover, it is the purpose of this research to determine the long term hematopoietic potential of such purified peripheral blood stem cells. If this research is successful, the long term goal is to develop large surface area devices which will efficiently and rapidly process the numbers of cells required for a full size transplant. Autologous transplant with purified peripheral blood stem cells will offer several advantages to patients: 1. Collection of peripheral blood could take place without general anesthesia, 2. The total number of stem cells collected and thereby transplanted will be greater, 3. In many diseases, the peripheral blood is less contaminated with tumor cells, 4. The purified CD34+ stem cells will serve as a purged source of engraftable material, and 5. Animal experiments indicate that more rapid engraftment may take place with purified stem cells. Because of these advantages, commercialization of these devices should be possible.